The semiconductor industry has experienced rapid growth due to continuous improvements in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, this improvement in integration density has come from repeated reductions in minimum feature size, which allows more components to be integrated into a given area. The reduced minimum feature size also typically results in higher device performance due to, for example, shorter distances electrical signals are carried.
Further, as semiconductor technologies have evolved, improved gate structures and processes for forming those gate structures have been created. One example of such improvement is the implementation of a metal gate electrode and various other layers, such as work-function tuning layers, into a gate structure. These improvements have led to further advancements in device performance.